xform_ipcomp.c revision 199899
1/* $FreeBSD: head/sys/netipsec/xform_ipcomp.c 199899 2009-11-29 10:53:34Z bz $ */ 2/* $OpenBSD: ip_ipcomp.c,v 1.1 2001/07/05 12:08:52 jjbg Exp $ */ 3 4/*- 5 * Copyright (c) 2001 Jean-Jacques Bernard-Gundol (jj@wabbitt.org) 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31/* IP payload compression protocol (IPComp), see RFC 2393 */ 32#include "opt_inet.h" 33#include "opt_inet6.h" 34 35#include <sys/param.h> 36#include <sys/systm.h> 37#include <sys/mbuf.h> 38#include <sys/lock.h> 39#include <sys/mutex.h> 40#include <sys/socket.h> 41#include <sys/kernel.h> 42#include <sys/protosw.h> 43#include <sys/sysctl.h> 44 45#include <netinet/in.h> 46#include <netinet/in_systm.h> 47#include <netinet/ip.h> 48#include <netinet/ip_var.h> 49 50#include <net/route.h> 51#include <net/vnet.h> 52 53#include <netipsec/ipsec.h> 54#include <netipsec/xform.h> 55 56#ifdef INET6 57#include <netinet/ip6.h> 58#include <netipsec/ipsec6.h> 59#endif 60 61#include <netipsec/ipcomp.h> 62#include <netipsec/ipcomp_var.h> 63 64#include <netipsec/key.h> 65#include <netipsec/key_debug.h> 66 67#include <opencrypto/cryptodev.h> 68#include <opencrypto/deflate.h> 69#include <opencrypto/xform.h> 70 71VNET_DEFINE(int, ipcomp_enable) = 0; 72VNET_DEFINE(struct ipcompstat, ipcompstat); 73 74SYSCTL_DECL(_net_inet_ipcomp); 75SYSCTL_VNET_INT(_net_inet_ipcomp, OID_AUTO, 76 ipcomp_enable, CTLFLAG_RW, &VNET_NAME(ipcomp_enable), 0, ""); 77SYSCTL_VNET_STRUCT(_net_inet_ipcomp, IPSECCTL_STATS, 78 stats, CTLFLAG_RD, &VNET_NAME(ipcompstat), ipcompstat, ""); 79 80static int ipcomp_input_cb(struct cryptop *crp); 81static int ipcomp_output_cb(struct cryptop *crp); 82 83struct comp_algo * 84ipcomp_algorithm_lookup(int alg) 85{ 86 if (alg >= IPCOMP_ALG_MAX) 87 return NULL; 88 switch (alg) { 89 case SADB_X_CALG_DEFLATE: 90 return &comp_algo_deflate; 91 } 92 return NULL; 93} 94 95/* 96 * ipcomp_init() is called when an CPI is being set up. 97 */ 98static int 99ipcomp_init(struct secasvar *sav, struct xformsw *xsp) 100{ 101 struct comp_algo *tcomp; 102 struct cryptoini cric; 103 104 /* NB: algorithm really comes in alg_enc and not alg_comp! */ 105 tcomp = ipcomp_algorithm_lookup(sav->alg_enc); 106 if (tcomp == NULL) { 107 DPRINTF(("%s: unsupported compression algorithm %d\n", __func__, 108 sav->alg_comp)); 109 return EINVAL; 110 } 111 sav->alg_comp = sav->alg_enc; /* set for doing histogram */ 112 sav->tdb_xform = xsp; 113 sav->tdb_compalgxform = tcomp; 114 115 /* Initialize crypto session */ 116 bzero(&cric, sizeof (cric)); 117 cric.cri_alg = sav->tdb_compalgxform->type; 118 119 return crypto_newsession(&sav->tdb_cryptoid, &cric, V_crypto_support); 120} 121 122/* 123 * ipcomp_zeroize() used when IPCA is deleted 124 */ 125static int 126ipcomp_zeroize(struct secasvar *sav) 127{ 128 int err; 129 130 err = crypto_freesession(sav->tdb_cryptoid); 131 sav->tdb_cryptoid = 0; 132 return err; 133} 134 135/* 136 * ipcomp_input() gets called to uncompress an input packet 137 */ 138static int 139ipcomp_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff) 140{ 141 struct tdb_crypto *tc; 142 struct cryptodesc *crdc; 143 struct cryptop *crp; 144 int hlen = IPCOMP_HLENGTH; 145 146 /* Get crypto descriptors */ 147 crp = crypto_getreq(1); 148 if (crp == NULL) { 149 m_freem(m); 150 DPRINTF(("%s: no crypto descriptors\n", __func__)); 151 V_ipcompstat.ipcomps_crypto++; 152 return ENOBUFS; 153 } 154 /* Get IPsec-specific opaque pointer */ 155 tc = (struct tdb_crypto *) malloc(sizeof (*tc), M_XDATA, M_NOWAIT|M_ZERO); 156 if (tc == NULL) { 157 m_freem(m); 158 crypto_freereq(crp); 159 DPRINTF(("%s: cannot allocate tdb_crypto\n", __func__)); 160 V_ipcompstat.ipcomps_crypto++; 161 return ENOBUFS; 162 } 163 crdc = crp->crp_desc; 164 165 crdc->crd_skip = skip + hlen; 166 crdc->crd_len = m->m_pkthdr.len - (skip + hlen); 167 crdc->crd_inject = skip; 168 169 tc->tc_ptr = 0; 170 171 /* Decompression operation */ 172 crdc->crd_alg = sav->tdb_compalgxform->type; 173 174 /* Crypto operation descriptor */ 175 crp->crp_ilen = m->m_pkthdr.len - (skip + hlen); 176 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 177 crp->crp_buf = (caddr_t) m; 178 crp->crp_callback = ipcomp_input_cb; 179 crp->crp_sid = sav->tdb_cryptoid; 180 crp->crp_opaque = (caddr_t) tc; 181 182 /* These are passed as-is to the callback */ 183 tc->tc_spi = sav->spi; 184 tc->tc_dst = sav->sah->saidx.dst; 185 tc->tc_proto = sav->sah->saidx.proto; 186 tc->tc_protoff = protoff; 187 tc->tc_skip = skip; 188 189 return crypto_dispatch(crp); 190} 191 192#ifdef INET6 193#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) do { \ 194 if (saidx->dst.sa.sa_family == AF_INET6) { \ 195 error = ipsec6_common_input_cb(m, sav, skip, protoff, mtag); \ 196 } else { \ 197 error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag); \ 198 } \ 199} while (0) 200#else 201#define IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, mtag) \ 202 (error = ipsec4_common_input_cb(m, sav, skip, protoff, mtag)) 203#endif 204 205/* 206 * IPComp input callback from the crypto driver. 207 */ 208static int 209ipcomp_input_cb(struct cryptop *crp) 210{ 211 struct cryptodesc *crd; 212 struct tdb_crypto *tc; 213 int skip, protoff; 214 struct mtag *mtag; 215 struct mbuf *m; 216 struct secasvar *sav; 217 struct secasindex *saidx; 218 int hlen = IPCOMP_HLENGTH, error, clen; 219 u_int8_t nproto; 220 caddr_t addr; 221 222 crd = crp->crp_desc; 223 224 tc = (struct tdb_crypto *) crp->crp_opaque; 225 IPSEC_ASSERT(tc != NULL, ("null opaque crypto data area!")); 226 skip = tc->tc_skip; 227 protoff = tc->tc_protoff; 228 mtag = (struct mtag *) tc->tc_ptr; 229 m = (struct mbuf *) crp->crp_buf; 230 231 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 232 if (sav == NULL) { 233 V_ipcompstat.ipcomps_notdb++; 234 DPRINTF(("%s: SA expired while in crypto\n", __func__)); 235 error = ENOBUFS; /*XXX*/ 236 goto bad; 237 } 238 239 saidx = &sav->sah->saidx; 240 IPSEC_ASSERT(saidx->dst.sa.sa_family == AF_INET || 241 saidx->dst.sa.sa_family == AF_INET6, 242 ("unexpected protocol family %u", saidx->dst.sa.sa_family)); 243 244 /* Check for crypto errors */ 245 if (crp->crp_etype) { 246 /* Reset the session ID */ 247 if (sav->tdb_cryptoid != 0) 248 sav->tdb_cryptoid = crp->crp_sid; 249 250 if (crp->crp_etype == EAGAIN) { 251 KEY_FREESAV(&sav); 252 error = crypto_dispatch(crp); 253 return error; 254 } 255 256 V_ipcompstat.ipcomps_noxform++; 257 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 258 error = crp->crp_etype; 259 goto bad; 260 } 261 /* Shouldn't happen... */ 262 if (m == NULL) { 263 V_ipcompstat.ipcomps_crypto++; 264 DPRINTF(("%s: null mbuf returned from crypto\n", __func__)); 265 error = EINVAL; 266 goto bad; 267 } 268 V_ipcompstat.ipcomps_hist[sav->alg_comp]++; 269 270 clen = crp->crp_olen; /* Length of data after processing */ 271 272 /* Release the crypto descriptors */ 273 free(tc, M_XDATA), tc = NULL; 274 crypto_freereq(crp), crp = NULL; 275 276 /* In case it's not done already, adjust the size of the mbuf chain */ 277 m->m_pkthdr.len = clen + hlen + skip; 278 279 if (m->m_len < skip + hlen && (m = m_pullup(m, skip + hlen)) == 0) { 280 V_ipcompstat.ipcomps_hdrops++; /*XXX*/ 281 DPRINTF(("%s: m_pullup failed\n", __func__)); 282 error = EINVAL; /*XXX*/ 283 goto bad; 284 } 285 286 /* Keep the next protocol field */ 287 addr = (caddr_t) mtod(m, struct ip *) + skip; 288 nproto = ((struct ipcomp *) addr)->comp_nxt; 289 290 /* Remove the IPCOMP header */ 291 error = m_striphdr(m, skip, hlen); 292 if (error) { 293 V_ipcompstat.ipcomps_hdrops++; 294 DPRINTF(("%s: bad mbuf chain, IPCA %s/%08lx\n", __func__, 295 ipsec_address(&sav->sah->saidx.dst), 296 (u_long) ntohl(sav->spi))); 297 goto bad; 298 } 299 300 /* Restore the Next Protocol field */ 301 m_copyback(m, protoff, sizeof (u_int8_t), (u_int8_t *) &nproto); 302 303 IPSEC_COMMON_INPUT_CB(m, sav, skip, protoff, NULL); 304 305 KEY_FREESAV(&sav); 306 return error; 307bad: 308 if (sav) 309 KEY_FREESAV(&sav); 310 if (m) 311 m_freem(m); 312 if (tc != NULL) 313 free(tc, M_XDATA); 314 if (crp) 315 crypto_freereq(crp); 316 return error; 317} 318 319/* 320 * IPComp output routine, called by ipsec[46]_process_packet() 321 */ 322static int 323ipcomp_output( 324 struct mbuf *m, 325 struct ipsecrequest *isr, 326 struct mbuf **mp, 327 int skip, 328 int protoff 329) 330{ 331 struct secasvar *sav; 332 struct comp_algo *ipcompx; 333 int error, ralen, maxpacketsize; 334 struct cryptodesc *crdc; 335 struct cryptop *crp; 336 struct tdb_crypto *tc; 337 338 sav = isr->sav; 339 IPSEC_ASSERT(sav != NULL, ("null SA")); 340 ipcompx = sav->tdb_compalgxform; 341 IPSEC_ASSERT(ipcompx != NULL, ("null compression xform")); 342 343 /* 344 * Do not touch the packet in case our payload to compress 345 * is lower than the minimal threshold of the compression 346 * alogrithm. We will just send out the data uncompressed. 347 * See RFC 3173, 2.2. Non-Expansion Policy. 348 */ 349 if (m->m_pkthdr.len <= ipcompx->minlen) { 350 /* XXX-BZ V_ipcompstat.threshold++; */ 351 return ipsec_process_done(m, isr); 352 } 353 354 ralen = m->m_pkthdr.len - skip; /* Raw payload length before comp. */ 355 V_ipcompstat.ipcomps_output++; 356 357 /* Check for maximum packet size violations. */ 358 switch (sav->sah->saidx.dst.sa.sa_family) { 359#ifdef INET 360 case AF_INET: 361 maxpacketsize = IP_MAXPACKET; 362 break; 363#endif /* INET */ 364#ifdef INET6 365 case AF_INET6: 366 maxpacketsize = IPV6_MAXPACKET; 367 break; 368#endif /* INET6 */ 369 default: 370 V_ipcompstat.ipcomps_nopf++; 371 DPRINTF(("%s: unknown/unsupported protocol family %d, " 372 "IPCA %s/%08lx\n", __func__, 373 sav->sah->saidx.dst.sa.sa_family, 374 ipsec_address(&sav->sah->saidx.dst), 375 (u_long) ntohl(sav->spi))); 376 error = EPFNOSUPPORT; 377 goto bad; 378 } 379 if (ralen + skip + IPCOMP_HLENGTH > maxpacketsize) { 380 V_ipcompstat.ipcomps_toobig++; 381 DPRINTF(("%s: packet in IPCA %s/%08lx got too big " 382 "(len %u, max len %u)\n", __func__, 383 ipsec_address(&sav->sah->saidx.dst), 384 (u_long) ntohl(sav->spi), 385 ralen + skip + IPCOMP_HLENGTH, maxpacketsize)); 386 error = EMSGSIZE; 387 goto bad; 388 } 389 390 /* Update the counters */ 391 V_ipcompstat.ipcomps_obytes += m->m_pkthdr.len - skip; 392 393 m = m_unshare(m, M_NOWAIT); 394 if (m == NULL) { 395 V_ipcompstat.ipcomps_hdrops++; 396 DPRINTF(("%s: cannot clone mbuf chain, IPCA %s/%08lx\n", 397 __func__, ipsec_address(&sav->sah->saidx.dst), 398 (u_long) ntohl(sav->spi))); 399 error = ENOBUFS; 400 goto bad; 401 } 402 403 /* Ok now, we can pass to the crypto processing. */ 404 405 /* Get crypto descriptors */ 406 crp = crypto_getreq(1); 407 if (crp == NULL) { 408 V_ipcompstat.ipcomps_crypto++; 409 DPRINTF(("%s: failed to acquire crypto descriptor\n",__func__)); 410 error = ENOBUFS; 411 goto bad; 412 } 413 crdc = crp->crp_desc; 414 415 /* Compression descriptor */ 416 crdc->crd_skip = skip; 417 crdc->crd_len = ralen; 418 crdc->crd_flags = CRD_F_COMP; 419 crdc->crd_inject = skip; 420 421 /* Compression operation */ 422 crdc->crd_alg = ipcompx->type; 423 424 /* IPsec-specific opaque crypto info */ 425 tc = (struct tdb_crypto *) malloc(sizeof(struct tdb_crypto), 426 M_XDATA, M_NOWAIT|M_ZERO); 427 if (tc == NULL) { 428 V_ipcompstat.ipcomps_crypto++; 429 DPRINTF(("%s: failed to allocate tdb_crypto\n", __func__)); 430 crypto_freereq(crp); 431 error = ENOBUFS; 432 goto bad; 433 } 434 435 tc->tc_isr = isr; 436 tc->tc_spi = sav->spi; 437 tc->tc_dst = sav->sah->saidx.dst; 438 tc->tc_proto = sav->sah->saidx.proto; 439 tc->tc_protoff = protoff; 440 tc->tc_skip = skip; 441 442 /* Crypto operation descriptor */ 443 crp->crp_ilen = m->m_pkthdr.len; /* Total input length */ 444 crp->crp_flags = CRYPTO_F_IMBUF | CRYPTO_F_CBIFSYNC; 445 crp->crp_buf = (caddr_t) m; 446 crp->crp_callback = ipcomp_output_cb; 447 crp->crp_opaque = (caddr_t) tc; 448 crp->crp_sid = sav->tdb_cryptoid; 449 450 return crypto_dispatch(crp); 451bad: 452 if (m) 453 m_freem(m); 454 return (error); 455} 456 457/* 458 * IPComp output callback from the crypto driver. 459 */ 460static int 461ipcomp_output_cb(struct cryptop *crp) 462{ 463 struct tdb_crypto *tc; 464 struct ipsecrequest *isr; 465 struct secasvar *sav; 466 struct mbuf *m; 467 int error, skip; 468 469 tc = (struct tdb_crypto *) crp->crp_opaque; 470 IPSEC_ASSERT(tc != NULL, ("null opaque data area!")); 471 m = (struct mbuf *) crp->crp_buf; 472 skip = tc->tc_skip; 473 474 isr = tc->tc_isr; 475 IPSECREQUEST_LOCK(isr); 476 sav = KEY_ALLOCSA(&tc->tc_dst, tc->tc_proto, tc->tc_spi); 477 if (sav == NULL) { 478 V_ipcompstat.ipcomps_notdb++; 479 DPRINTF(("%s: SA expired while in crypto\n", __func__)); 480 error = ENOBUFS; /*XXX*/ 481 goto bad; 482 } 483 IPSEC_ASSERT(isr->sav == sav, ("SA changed\n")); 484 485 /* Check for crypto errors */ 486 if (crp->crp_etype) { 487 /* Reset session ID */ 488 if (sav->tdb_cryptoid != 0) 489 sav->tdb_cryptoid = crp->crp_sid; 490 491 if (crp->crp_etype == EAGAIN) { 492 KEY_FREESAV(&sav); 493 IPSECREQUEST_UNLOCK(isr); 494 return crypto_dispatch(crp); 495 } 496 V_ipcompstat.ipcomps_noxform++; 497 DPRINTF(("%s: crypto error %d\n", __func__, crp->crp_etype)); 498 error = crp->crp_etype; 499 goto bad; 500 } 501 /* Shouldn't happen... */ 502 if (m == NULL) { 503 V_ipcompstat.ipcomps_crypto++; 504 DPRINTF(("%s: bogus return buffer from crypto\n", __func__)); 505 error = EINVAL; 506 goto bad; 507 } 508 V_ipcompstat.ipcomps_hist[sav->alg_comp]++; 509 510 if (crp->crp_ilen - skip > crp->crp_olen) { 511 struct mbuf *mo; 512 struct ipcomp *ipcomp; 513 int roff; 514 uint8_t prot; 515 516 /* Compression helped, inject IPCOMP header. */ 517 mo = m_makespace(m, skip, IPCOMP_HLENGTH, &roff); 518 if (mo == NULL) { 519 V_ipcompstat.ipcomps_wrap++; 520 DPRINTF(("%s: IPCOMP header inject failed for IPCA %s/%08lx\n", 521 __func__, ipsec_address(&sav->sah->saidx.dst), 522 (u_long) ntohl(sav->spi))); 523 error = ENOBUFS; 524 goto bad; 525 } 526 ipcomp = (struct ipcomp *)(mtod(mo, caddr_t) + roff); 527 528 /* Initialize the IPCOMP header */ 529 /* XXX alignment always correct? */ 530 switch (sav->sah->saidx.dst.sa.sa_family) { 531#ifdef INET 532 case AF_INET: 533 ipcomp->comp_nxt = mtod(m, struct ip *)->ip_p; 534 break; 535#endif /* INET */ 536#ifdef INET6 537 case AF_INET6: 538 ipcomp->comp_nxt = mtod(m, struct ip6_hdr *)->ip6_nxt; 539 break; 540#endif 541 } 542 ipcomp->comp_flags = 0; 543 ipcomp->comp_cpi = htons((u_int16_t) ntohl(sav->spi)); 544 545 /* Fix Next Protocol in IPv4/IPv6 header */ 546 prot = IPPROTO_IPCOMP; 547 m_copyback(m, tc->tc_protoff, sizeof(u_int8_t), 548 (u_char *)&prot); 549 550 /* Adjust the length in the IP header */ 551 switch (sav->sah->saidx.dst.sa.sa_family) { 552#ifdef INET 553 case AF_INET: 554 mtod(m, struct ip *)->ip_len = htons(m->m_pkthdr.len); 555 break; 556#endif /* INET */ 557#ifdef INET6 558 case AF_INET6: 559 mtod(m, struct ip6_hdr *)->ip6_plen = 560 htons(m->m_pkthdr.len) - sizeof(struct ip6_hdr); 561 break; 562#endif /* INET6 */ 563 default: 564 V_ipcompstat.ipcomps_nopf++; 565 DPRINTF(("%s: unknown/unsupported protocol " 566 "family %d, IPCA %s/%08lx\n", __func__, 567 sav->sah->saidx.dst.sa.sa_family, 568 ipsec_address(&sav->sah->saidx.dst), 569 (u_long) ntohl(sav->spi))); 570 error = EPFNOSUPPORT; 571 goto bad; 572 } 573 } else { 574 /* compression was useless, we have lost time */ 575 /* XXX add statistic */ 576 /* XXX remember state to not compress the next couple 577 * of packets, RFC 3173, 2.2. Non-Expansion Policy */ 578 } 579 580 /* Release the crypto descriptor */ 581 free(tc, M_XDATA); 582 crypto_freereq(crp); 583 584 /* NB: m is reclaimed by ipsec_process_done. */ 585 error = ipsec_process_done(m, isr); 586 KEY_FREESAV(&sav); 587 IPSECREQUEST_UNLOCK(isr); 588 return error; 589bad: 590 if (sav) 591 KEY_FREESAV(&sav); 592 IPSECREQUEST_UNLOCK(isr); 593 if (m) 594 m_freem(m); 595 free(tc, M_XDATA); 596 crypto_freereq(crp); 597 return error; 598} 599 600static struct xformsw ipcomp_xformsw = { 601 XF_IPCOMP, XFT_COMP, "IPcomp", 602 ipcomp_init, ipcomp_zeroize, ipcomp_input, 603 ipcomp_output 604}; 605 606static void 607ipcomp_attach(void) 608{ 609 610 xform_register(&ipcomp_xformsw); 611} 612 613SYSINIT(ipcomp_xform_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_MIDDLE, ipcomp_attach, NULL); 614